The proposed research will investigate the nature of the human sentence comprehension system by examining the influence of pragmatic plausibility on the computation of syntactic structure and sentence meaning. The experiments will specifically consider the relationship between plausibility computation, syntactic processing, and individual differences in working memory capacity. Basic behavioral measures of reading difficulty (self-paced reading, continuous anomaly judgment) will be used, along with two neurological measures, event-related potential (ERP) recording and event-related functional magnetic resonance imaging (er-fMRI). These measures will be combined to yield more precise data about behavior and about the functional neuroanatomical loci of syntactic and semantic processes than has been possible with any of the measures alone. The results of these experiments have implications for nearly all theories of sentence processing and ambiguity resolution, as well as for the understanding of individual differences in language comprehension ability and of language impairment due to brain injury. The results should lead to more finely-specified psycholinguistic, neurological, and computational models of human language processing.